Chickpea (Cicer arietinum) and Soybean (Glycine max) Hulls: Byproducts with Potential Use as a Source of High Value-Added Food Products

Abstract

The objective of this research was to evaluate the potential as a source of high value-added products in terms of dietary fiber, phenolics and antioxidant capacity of hull byproducts generated from chickpea and soybean processing. Total dietary fiber by enzymatic–gravimetric method was evaluated and content ranged from 70.37 to 76.94 % showing soybean hull the highest levels. In addition, the total phenols (Folin-Ciocalteu), total flavonoids (AlCl3) and condensed tannins (Vanillin-H2SO4) were evaluated as part of phenolic analysis, while antioxidant capacity was evaluated using DPPH and ABTS radicals. Phenolics ranged from 0.11 to 1.75, 0.42 to 1.21 and 5.90 to 7.91 mg/g in total phenols, total flavonoids and condensed tannins, respectively. On the other hand, DPPH and ABTS ranged from 2.35 to 5.28 and from 6.52 to 14.87 μmolTE/g, respectively. Soybean showed the highest levels of phenolics and antioxidant capacity. In the free fraction were obtained the higher values in total phenolics, condensed tannins and ABTS, while the bound fraction showed higher values in total flavonoids and ABTS. Chickpea and soybean hulls showed to be potential byproducts as a source of dietary fiber and phenolics with antioxidant capacity. Information generated in this study is relevant, since proposed an alternative use to the chickpea and soybean industries to use their byproducts for obtaining high value-added products.